MANILA (AFP) – Archaeologists have found a foot bone that could prove the Philippines was first settled by humans 67,000 years ago, thousands of years earlier than previously thought, the National Museum said Tuesday.

The bone, found in an extensive cave network, predates the 47,000-year-old Tabon Man that is previously known as the first human to have lived in the country, said Taj Vitales, a researcher with the museum's archaeology section.

"This would make it the oldest human remains ever found in the Philippines," Vitales told AFP.

Archaeologists from the University of the Philippines and the National Museum dug up the third metatarsal bone of the right foot in 2007 in the Callao caves near Penablanca, about 335 kilometres (210 miles) north of Manila.

Their report on "Callao Man" was released in the latest edition of the Journal of Human Evolution after tests in France established the fossil's age, said professor Armand Mijares, the expedition leader.

"It broke the barriers," Mijares said, explaining that previous evidence put the first human settlements in the Philippines and nearby islands around Tabon Man.

"It pushed that back to nearly 70,000 years."

Cut marks on bones of deer and wild boar found around it suggest Callao Man could have hunted and was skilled with tools, although no cutting or other implements were found during the dig, according to Mijares.

"This individual was small-bodied. It's difficult to say whether he was male or female," he said.

Mijares stressed the finding that Callao Man belongs to Homo sapiens was still only provisional. Some of the bone's features were similar to Homo habilis and Homo floresiensis -- which are distinct species from humans.

Existing evidence suggests that Homo sapiens, modern man, first appeared in Africa about 200,000 years ago.

Homo habilis is considered a predecessor to Homo sapiens while Homo floresiensis is thought to be a short, human-like species that once existed on an Indonesian island in the Late Pleistocene stage.

To determine whether Callao Man was human, Mijares said his team planned to secure permits to pursue further excavations in the Callao caves and hopefully find other parts of the skeleton, tools, or fossils of other potential humans.

Mijares said Callao Man also shared some features of today's Aetas, a short, curly-haired and dark-skinned people who are thought to be directly descended from the first inhabitants of the Philippines.

The discovery also suggests that raft or boat-building crafts would have been around at that time.

"The hypothesis is that the Philippines, which is surrounded by bodies of water, was first reached by humans aboard rafts," Vitales said.

But he said there was no consensus on whether the first settlers came from mainland Asia, neighbouring Southeast Asian islands or elsewhere.

Archaeologists have been exploring the Callao caves system since the 1970s. "Generally caves are used as habitations and burial sites," Vitales said.

Tabon Man, the fossilised fragments of a skull and jawbone from three individuals, was discovered along with stone flake tools by a National Museum team in a cave on the western Philippine island of Palawan in May 1962.